Crucible for electric furnaces



Sept. 29, 1925. 1,555,356

M. S. CLAWSON CRUCIBLE FOR ELECTRIC FURNACES Filed July 1923 fizayroe L5,: Cla /50p W/ T/I/[JS IN VEN TOR.

A TTORNEY Patented Sept. 29, 1925 UNITED STATES PATENT OFFICE.

MONROE S. CLAWSON, 0F UPPER MONTCLAIR, NEW JERSEY.

'CBUCIBLE FOR ELECTRIC FURNACES.

Application filed July 9,

To all whom it may concern Be it known that I, Mormon S. CnAWsoN, a citizen of the United States, residing at Upper Montclair, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Crucibles for Electric Furnaces, of which the following is a specification.

This invention relates to crucibles for use in connection with electric furnaces and especially furnacesof the type shown in my Patent No. 1,806,948.

The structure forming the subject-matter of the above mentioned patent consists of movably mounted water cooled heads between which is mounted a crucible or resistor held in ,firm engagement with the heads by a clamping means. In the use of such a furnace I have discovered that the ordinary flat or beveled ended crucible chips off at the edges or corners and is liable to fracture at other places when strain is applied to the clamping means to insure the making of a perfect electrical contact between the heads and the crucible.

It is to remedy the above mentioned del'ect that I have made the present invention which has for its essential object the pro vision of a crucible or resistor having 6011- vex ends conformingly engaging within concavities in the confronting faces of the heads so that the endwise pressure exerted by theclamping means will be applied toward the center of the crucible as I have discovered that this arrangement eliminates the usual chipping and breaking.

An additional'object is the provision of a crucible of this character which will be simple and inexpensive to make, eilicient and durable in use, and a general improvement inthe art.

lVith the above and other objects and advantages in view, the invention consists in the detailed construction to be hereinafter more fully described and claimed, and illustrated in the accompanying drawings in which:

Figure 1 is a plan view of my crucible associated with an electric furnace.

Figure 2 is a horizontal section through the heads and crucible. 1

Figure 3 is a vertical section on the line 33 of Figure 2.

Referring more particularly to the drawings, I have illustrated a furnace including a support A on which are pivoted arms B 1923. Serial No. 650,270.

carrying water cooled heads C. The heads are designed to be engaged against opposite ends of the crucible and are clamped into engagement therewith by some suitable means such, for instance, as the rod D which passes through both arms B and which is 1 convex, as shown, and are in reality portions of a sphere. The confronting faces of the heads G are formed with corresponding concavities 13 so that when the heads are clamped against the ends of the crucible there will be a conforming engagement.

In use it is obvious that the pressure of the heads against the ends of the crucible will be directed toward the center and in accordance with well known principles it is apparent that the strain will be evenly distributed. Actual demonstration has proved that crucibles constructed inthis manner are not subject to breakage as are those of ordinary formation and consequently have a long life.

While I have shown and described the preferred embodiment of the invention, it is of course to be understood that I reserve the right to make all such changes in the materials, size and shape as may be found.

advisable and in regard to the curvature of the. ends it is apparent that variations in the degree thereof may be resorted to as allsuch modifications or changes would fall within the scope of the claims hereunto appended.

I claim: 1 v

1. A crucible of the open topped type consisting of an elongated body having convex ends.

2. A crucible for electric furnaces of the type having spaced heads, comprisin the furnace. 1 3. In combination with a furnace including a pair of heads urged toward each other an open topped body having convex ends a apted to fit within'concavities in the heads of 4. In combination with a furnace including a pair of heads urged toward each other and having concaved confronting faces, a crucible having convex ends conformingly fitting within the concaved faces of the heads, said convex ends being portions of a sphere.

5. In combination with pressed together heads of an electric furnace, a resistor arranged between and clamped by said heads, the ends of the resistor being convex and engaging within corresponding concavities in the heads whereby the pressure of the heads upon the resistor will be directed toward the center thereof.

6. A boat type crucible adapted for interposition between the current carrying heads of an electric furnace and having partially spherical ends to withstand the pressure applied to the heads for maintaining contact 0 thereof with the crucible.

7. The combination with an'electric furnace of the type having heads, of a boat type crucible having partially spherical ends, the heads being .concaved for conforming engagement with said partially spherical ends, said ends acting to distribute the strains applied thereto and to prevent crushing of the crucible.

S. A boat type crucible adapted for use interposed between heads pressed toward each other, having its ends shaped to distribute the strains produced by the actual engagement of the heads thereagainst.

In testimony whereof I hereto afiix my signature.

"MONROE S. CLAWVSON. 

